At present, the known ways of observing and identifying mineral samples by some optical instruments are almost all to place samples on an optical surface coated with refracting oil, fix and rotate the mineral samples by hands, and then observe directly from the eyepiece window by eyes to obtain readings at different angles of rotation of the samples. Such ways not only are complex in operation and low in efficiency and highly depend upon the proficiency and experience of the observers, but also fail to realize quantified rotation of samples. A too narrow eyepiece window also brings great inconvenience to the observation and identification, and the observed image can not be saved. Meanwhile, due to the unsealed sample observation environment, it is unable to avoid the stray light interference from the external environment during the rotation of samples by fingers, and also difficult to ensure close and stable contact between undetermined mineral samples to be detected and the optical surface so that the observers can not observe the accurate optical characteristics of the mineral samples to be detected from the optical instruments. Consequently, there are large errors in the obtained identification results of the minerals. When small mineral samples are fixed and rotated by hands, the fingers are likely to touch the virulent refracting oil so that the physical health of those who are identifying the samples is threatened; and the environment is polluted.
Utility Model Patent CN200420017243.8, titled “JEWEL FIXING AND ROTATING APPARATUS”, discloses an apparatus for fixing and rotating jewels, where a left positioning slider guide rail and a right positioning slider guide rail are respectively provided on two sides of a main frame, a rotary dial central body is inserted into a center hole of the main frame, and a jewel positioning head fixing hole is provided at a jewel pressing rod shaft end of a jewel pressing rod. When in use, the apparatus is fixed on an optical instrument by adjusting the rotating and positioning screw stem handles at two ends first, then an external thread lifting bolt handle is rotated to adjust the up-down position of the jewel positioning head so that the jewel is compressed and fixed, and finally the jewel can be observed from various angles by rotating the rotary dial. This utility model highly depends upon the proficiency and experience of the detectors, fails to realize reliable fixation of the optical instrument and also accurate and automatic quantified rotation of samples, fails to avoid stray light interference in the contact surfaces and the eyepiece, and also fails to save the observed results.